Amy Winehouse released just two albums in her lifetime and performed only a handful of gigs in the U.S. at the peak of her popularity in 2007. But just days after Winehouse's death at age 27 of yet-undetermined causes, she is already being spoken of as an iconic singer whose unique fusion of jazz, soul, R&B, girl-group swing and hip-hop swagger has inspired a whole generation of singers.

"I think that her success at the time when Back to Black came out here, and the aftermath of that, continues [to have an impact]," said Sirius satellite radio host Jenny Eliscu, a contributing editor at Rolling Stone magazine who wrote a cover story on Winehouse in 2007 that chronicled the then 23-year-old's chaotic personal life. "It reminded people that there was a way to do a retro style the way she did it and have it sound totally modern. It had that instant-classic factor."

Eliscu said the sound of Back to Black was so riveting at the time because it pulled off that rare trick in music: It reminded fans of all the great music that influenced her without sounding like she was merely copying her heroes.

"Winehouse opened the door to music that sounds like Adele," Eliscu said, referring to the "Rolling in the Deep" star who wrote a touching tribute to the "Rehab" singer on Monday. "In the long term, the thing we will see is whatever door Adele opens by having Winehouse open the door for her will then be opened for someone else, whether it's Winehouse's retro soul [goddaughter Dionne Bromfield] or that kind of sound that would not have returned to the mainstream if not for the great songs in the modern style that [Winehouse] wrote."

As her small catalog raced up the iTunes charts in the wake of her death, and Back to Black was tipped to re-enter the Billboard 200 on Wednesday (after tallying just one day of posthumous sales), Billboard associate director of charts/radio Gary Trust said Winehouse's influence is destined to be much larger than mere sales.

"She only had two albums on the Billboard 200 [2006's Back to Black and 2003's Frank] and two songs on the Hot 100 ['Rehab' and 'You Know I'm No Good'], and you would think she was a one-hit wonder, but she really did bring that sound — that soulful British pop — to a whole new generation," said Trust, referring to such singers as Adele, Jessie J. and Duffy, who have all put their own spin on the sound that Winehouse pioneered.

"It's more of a common sound now, and it's a testament to her that people consider her such an influence when she had only had one big hit," he said. "They got into her music deeply, and that influence is much bigger than her chart history shows."

While Winehouse will surely pop up on the Billboard album charts this week, Trust predicted her presence will be bigger still next week.

Trust also said the iTunes bump is yet another example of how big an impression Winehouse made in a short time. "This is the biggest thing since Michael Jackson died, and now in the digital era, you can sit at your computer and find out about something like this on Facebook and then be on another screen buying the songs on iTunes."